I'm trying to detect a file's line endings (\r\n for DOS, \r for Mac and \n for
Unix as I'm sure y'all know).
Is there any easy way to do this?
I don't want to slurp the whole file, because it could be 14 MB or more, so I
wanted to read in chunks until I got to a line break. However I can see a
potential problem ending a chunk half way through a DOS \r\n, so then you just
get \r which makes it look like a Mac formatted file.
Anyway, I started to roll my own code for it, and because I'm new to Perl I
hoped that one of you kind souls would have a quick look (below) to check that
I've got the right idea of how to do this sort of thing with Perl. (It seems to
work with my tests, but that doesn't necessarily mean that it is a robust
method!)
Also, I assume that one can pass a file handle to a sub-routine?
$/ = &sniff_line_endings(<INFILE>) ;
Many thanks,
James Harvard
open (INFILE,$filename) or die "Couldn't open" ;
$/ = \50 ;
my $taste = '' ;
my $lb = undef ;
until ($lb) {
$taste .= <INFILE> ;
if ($taste =~ /\r\n/) {
$lb = "\r\n" ;
# DOS line endings
} elsif ($taste =~ /\r(?!$)/) {
$lb = "\r" ;
# Mac line endings
} elsif ($taste =~ /\n/) {
$lb = "\n" ;
# Unix line endings
}
}
$/ = $lb ;
seek INFILE, 0, 0 ; # reset the file read pointer
# do while(<INFILE>) stuff
